Information handling system flexible display rotational orientation monitoring and management

ABSTRACT

A portable information handling system folds a flexible display over a hinge and selectively engages a brake that restricts hinge movement if a predetermined condition exists, such as a predetermined thermal state associate with potential damage to the flexible display. Heating and cooling elements increase or decrease the flexible display thermal state to fall within a constraint that supports folding and releases the hinge brake.

CROSS-REFERENCE TO RELATED APPLICATION(S)

U.S. patent application Ser. No. ______, entitled “Information HandlingSystem Flexible Display Operating Condition Monitoring and Management”by inventors Yagiz Can Yildiz, Christopher A. Torres, Kevin M. Turchin,and Gerald R. Pelissier, Attorney Docket No. DC-115763.01, filed on evendate herewith, describes exemplary methods and systems and isincorporated by reference in its entirety.

U.S. patent application Ser. No. ______, entitled “Information HandlingSystem Flexible Display Smart Stylus” by inventors Yagiz Can Yildiz,Christopher A. Tones, Kevin M. Turchin, Gerald R. Pelissier, and Rex W.Bryant, Attorney Docket No. DC-115764.01, filed on even date herewith,describes exemplary methods and systems and is incorporated by referencein its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates in general to the field of portableinformation handling systems, and more particularly to informationhandling system flexible display rotational orientation monitoring andmanagement.

Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Portable information handling systems integrate processing components, adisplay and a power source in a portable housing to support mobileoperations. Portable information handling systems allow end users tocarry a system between meetings, during travel, and between home andoffice locations so that an end user has access to processingcapabilities while mobile. Tablet configurations typically expose atouchscreen display on a planar housing that both outputs information asvisual images and accepts inputs as touches. Convertible configurationstypically include multiple separate housing portions that rotationallycouple to each other so that the system converts between closed and openpositions. For example, a main housing portion integrates processingcomponents and a keyboard and rotationally couples with hinges to a lidhousing portion that integrates a display. In clamshell configuration,the lid housing portion rotates approximately ninety degrees to a raisedposition above the main housing portion so that an end user can typeinputs while viewing the display. After usage, convertible informationhandling systems rotate the lid housing portion over the main housingportion to protect the keyboard and display, thus reducing the systemfootprint for improved storage and mobility.

Recently, market interest has increased for highly mobile informationhandling systems that have increased display surfaces to presentinformation as visual images. To improve mobility and display viewingareas, a second display is integrated in the housing instead of akeyboard. In such systems, rotation to the clamshell configurationallows the user to type at a virtual keyboard presented on ahorizontally-oriented display while viewing information at avertically-oriented display. By further rotating the housing to a tabletconfiguration, both displays are available to present visualinformation. In low Z-height systems having minimal hinge spacingbetween the housing portions, only a small space exists between thedisplays to disrupt viewing visual images across both displays.

Generally, dual-display portable information handling systems share manyof the problems faced by conventional convertible systems. One problemthat tends to arise is that processing components dissipate power asheat that has to be rejected from portable housings. Often in lowZ-height systems, thermal management is performed with passive transferrather than active transfer, such as a cooling fan that rejects thermalenergy with a cooling airflow. Passive thermal rejection tends toinvolve heat pipes and other thermal transfer conduits that reject atleast some thermal energy across the outer skin of the housing. Inaddition, passive management may control the amount of thermal energygenerated by processing components to reduce internal and skintemperatures. To aid in thermal management, INTEL provides a DynamicPlatform Thermal Framework (DPTF) that manages processing componentoperation to maintain thermal constraints. A recent update to DPTFadjusts processing component operation based upon system orientation,which tends to impact how well thermal energy dissipates from thehousing surface.

Another problem that tends to arise with distributing displays betweentwo separate housing portions tends to break up presentation of visualinformation. Although a single visual image may stretch across bothdisplays, the break formed in the middle of the visual image tends todisrupt end user enjoyment and consumption of presented content. Forinstance, a dual display information handling system opened to a tabletconfiguration can present a movie across both displays, however, thecontent is disrupted through a central portion.

One solution that helps present visual information across rotationallycoupled housing portions is the use of a flexible display that foldsacross the housing portions. Specifically, organic light emitting diode(OLED) display films present visual information by applying current tored, green and blue organic material disposed in each of plural pixels.When an OLED film is disposed over a plastic substrate (POLED), theresulting flexible display film can integrate over a hinge to fold aboutthe hinge when the housing portions are rotated from closed to openpositions. Thus, in an open position, the display surface spreads acrossboth housing portions to allow end user viewing of content without abreak at the hinge fold location.

Although POLED displays fold across a hinge, the material tends to besensitive to environmental conditions and folding stresses, such as fromcompressive and tensile forces translated by movement of the housingportions and hinge. For instance, in both high and low temperatureextremes, POLED folding may result in damage, such as warpage, thatdistorts visual images presented at the display. Further, the responseof a POLED to folding forces may vary substantially based uponoperational conditions to which the POLED is subjected. For instance, aPOLED display that remains folded for an extended amount of time tendsto develop a memory of the folded condition that resists unfolding,which can lead to damage of the POLED at unfolding.

Generally, the fold area of a flexible display, such as the area overtop of a hinge, is supported by a flexible support that raises intoposition under the flexible display in the tablet configuration andyields as the display folds. When the flexible display is flat, failureto provide sufficient support underneath can result in damage to thedisplay from end user presses, such as with a finger or stylus input.However, any support provided under the display typically has to moveout of the way of the display as the display folds to avoid exertingcompressive or tensile stress on the display. The amount of pressurethat a display can withstand in its folding portion tends to vary basedupon operating conditions.

SUMMARY OF THE INVENTION

Therefore, a need has arisen for a system and method which monitors andmanages flexible display operating conditions.

In accordance with the present invention, a system and method areprovided which substantially reduce the disadvantages and problemsassociated with previous methods and systems for monitoring and managingflexible display operating conditions. A display manager monitors andstores operating conditions at a display, applies the stored operatingconditions to determine display operating constraints, and applies thecurrent operating conditions against the operating constraints to adaptdisplay operations, such a display fold orientation or touch pressuresat the display.

More specifically, an information handling system processes informationwith processing components disposed in a housing, such as a housinghaving separate portions rotationally coupled by a hinge assembly. Aflexible display is disposed over the housing portions and hinge toprovide a tablet configuration with the housing portions in an openposition and to fold over the hinge when the housing portions rotate tothe closed position. A display manager stored in non-transitory memoryand executed on a processor of the information handling system monitorsplural sensors that sense display operating conditions and store thesensed operating conditions to model display operating constraintsassociated with limits enforced for display operations. For instance,the plural sensors may include temperature sensors that detect a thermalstate of the display, rotation sensors that detect a rotationalorientation of the housing portions, and pressure sensors that detectpressures associated with touches at the display. Display operatingconditions may be adapted based upon a temperature constraint by heatingor cooling the display or locking the display in a current position,such as a folded or flat position, until the temperature constraint isalleviated. As another example, a pressure condition may be adaptedbased upon a detected stylus usage by adjusting the writing tip sizeused by the stylus or providing the end user with an audible, haptic orvisual warning.

The present invention provides a number of important technicaladvantages. One example of an important technical advantage is that aninformation handling system having a folding display has improved lifeand robustness by monitoring display operating conditions over time andapplying the operating conditions to determine operating constraintsrelative to sensed conditions, such as temperature, fold angle and touchinputs. For instance, a hinge brake interfaced with a hinge restrictshousing portion rotation that folds or unfolds a flexible display whenthe flexible display temperature exceeds a threshold temperature range,indicating that damage may occur to the flexible display if it folds orunfolds. As another example, active heating or cooling of the flexibledisplay to achieve a thermal state within the threshold temperaturerange to reduce any impact on an end user, such as by maintaining thetemperature range at all times or rapidly achieving the temperaturerange when an end user attempts to adjust the housing portion rotationalorientation. In one example embodiment, flexible display thermal stateis adapted by altering operations of processing components of theinformation handling system, such as by change display brightness,processor operating speed, or executing non-productive code thatgenerates thermal energy.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood, and its numerousobjects, features and advantages made apparent to those skilled in theart by referencing the accompanying drawings. The use of the samereference number throughout the several figures designates a like orsimilar element.

FIG. 1 depicts an exploded view of an information handling system havingflexible display monitoring and management;

FIG. 2 depicts a block diagram of hardware, firmware and software layersof an information handling system having flexible display monitoring andmanagement;

FIG. 3 depicts a flexible touchscreen display divided up into fifteenregions that are each monitored and tracked separately for detectedoperating conditions;

FIG. 4 depicts an example thermal model table that lists thermalconditions expected for display film operating conditions based upon theplural regions;

FIG. 5 depicts a panel characterization table having examples of storedinformation gathered from sensors that monitor the flexible display;

FIG. 6 depicts a flow diagram of a process for monitoring and adapting aflexible display film operation based upon thermal operating conditionsand constraints;

FIG. 7 depicts a flow diagram of a process for adapting informationhandling system operating conditions in response to detection ofnon-ideal thermal conditions;

FIG. 8 depicts a flow diagram of a process for adapting informationhandling system operating conditions based upon time in a foldedposition;

FIGS. 9A and 9B depict an example of flexible display film fold radiuschanges related to time in a folded position;

FIGS. 10A, 10B, 10C and 10D depict side cutaway views of a stylus havingautomated interactions with a flexible display film;

FIGS. 11A and 11B depict side cutaway views of the stylus having anextended tip configured to selectively extend;

FIG. 12 depicts a side perspective view of monitoring of flexibledisplay film surface planarity by measuring a distance with a distancesensor;

FIG. 13 depicts an example of a relationship between pressures detectedat a stylus tip and load placed on the flexible display; and

FIG. 14 depicts a flow diagram of a process for managing a stylus tipengagement at a flexible display film.

DETAILED DESCRIPTION

An information handling system flexible display operating conditions aremonitored to manage flexible display operations within operatingconstraints that are adjusted for flexible display usage over time. Forpurposes of this disclosure, an information handling system may includeany instrumentality or aggregate of instrumentalities operable tocompute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize any form of information, intelligence, or data for business,scientific, control, or other purposes. For example, an informationhandling system may be a personal computer, a network storage device, orany other suitable device and may vary in size, shape, performance,functionality, and price. The information handling system may includerandom access memory (RAM), one or more processing resources such as acentral processing unit (CPU) or hardware or software control logic,ROM, and/or other types of nonvolatile memory. Additional components ofthe information handling system may include one or more disk drives, oneor more network ports for communicating with external devices as well asvarious input and output (I/O) devices, such as a keyboard, a mouse, anda video display. The information handling system may also include one ormore buses operable to transmit communications between the varioushardware components.

Referring now to FIG. 1, an exploded view depicts an informationhandling system 10 having flexible display monitoring and management.Information handling system 10 is built into a housing 12 havingopposing housing portions 14 rotationally coupled by a hinge assembly36. In the example embodiment, one housing portion 14 contains amotherboard 16 and the opposing housing portion contains a daughterboard18, which interface across hinge assembly 36 through a flexible cable28. Motherboard 16 includes wirelines that interface processingcomponents mounted to its surface. A central processing unit (CPU) 20executes instructions that process information in cooperation with arandom access memory (RAM) 22 that stores the instructions andinformation. A wireless network interface card (WNIC) includes wirelesscommunication components that support communication of information bywireless signals, such as wireless local area network (WLAN), wirelesswide area network (WWAN) and wireless personal area network (WPAN)communications. A solid state drive (SSD) 26 provides non-transitorymemory for persistent storage of information, such as of an operatingsystem and applications. Daughterboard 18 includes wirelines thatinterface other processing components, such as a graphics processingunit (GPU) 30 and embedded controller 32. In the example embodiment,embedded controller 32 manages application of power to the processingcomponents from an integrated battery 34.

In operation, information handling system 10 applies power managed byembedded controller 32 to initiate a boot process to reach anoperational state. For instance, at a press of a power button or otherpower up indication, embedded controller 32 draws power from battery 34and executes pre-boot code to power up CPU 20 and RAM 22. Undermanagement of the preboot code, a basic input/output system (BIOS) orother management code initiates retrieval of an operating system fromSSD 26 to an active state for operational control of the processingcomponents. CPU 20 provides visual information defined by the operatingsystem to GPU 30, which processes the visual information into pixelvalues that define visual images for presentation at a flexibletouchscreen display 44. Flexible touchscreen display 44 detects touchesas inputs that are communicated through embedded controller 32 to CPU20. In various embodiments, various combinations of processingcomponents may be used and distributed in housing 12 to provide aninformation handling system having a desired capability and size.

Flexible touchscreen display 44 is, for example, a plastic organic lightemitting diode (POLED) display film that is supported over top ofhousing 12 with an integrated flexible plastic substrate. In a planartablet position, such as depicted in the example embodiment, flexibletouchscreen display 44 lays across both housing portions 14 in one planeacting as a tablet with a contiguous viewing area. By folding housingportions 14 at hinge assembly 36, flexible touchscreen display 44 foldsat a central portion to allow a transition from the tablet position to aclamshell position, such as at approximately ninety degrees of rotation,and a closed position having opposing housing portions in closeproximity to each other, such as at approximately 180 degrees ofrotation. Although POLED material is designed to fold with hingeassembly 36, the impact that a fold has on the longevity of the POLEDmaterial may vary greatly based upon operating conditions at flexibletouchscreen display 44, such as the temperature, compressive or tensilestresses present, external pressure pressed against the display film andhistorical usage patterns. Folding of flexible touchscreen display 44 inoperating conditions outside of operating constraints can cause damageto the POLED display film.

In order to characterize operating constraints, code executing oninformation handling system 10, such as embedded code stored as firmwarethat executes on embedded controller 32, BIOS stored in SSD 26 and/or adriver executing with an operating system execution on CPU 20, monitorsoperating conditions over time and applies the operating conditions tomodel operating constraints of flexible touchscreen display 44. Forexample, a rotational orientation sensor 38 detects rotationalorientation of housing portions 14 to track an amount of rotation, timein a rotational position and a number of rotations. Rotationalorientation sensor 38 may measure hinge position, such as by countinggear motion and position, may measure relative gravitational positionsof housing portions 14, such as with accelerometer gyroscopes in eachhousing portion 14, or may use other relative positional measurements ofhousing portions 14. As another example, temperature sensors 46distributed through housing 12 and at flexible touchscreen display 44determine a thermal state of the POLED material, which tends to sufferdamage if the plastic substrate has an excessive or too low temperature.Thermal conditions at flexible touchscreen display 44 may be measureddirectly or estimated by other nearby temperature readings. In addition,thermal conditions at flexible touchscreen display 44 may be estimatedwith virtual temperature sensors, such as by estimating thermalconditions from power dissipated by nearby processing components.

Another example of an operating condition sensor is found through theinteraction of a stylus 52 with a touch detection sensor integrated inflexible touchscreen display 44. Stylus 52 has a pen-shaped housing 54that terminates at one end with a writing tip 56 having a tip designedto touch at a precise location of flexible touchscreen display 44. Aprocessor 58 interfaces with the tip to provide selection of the tiptype, such as the size of the tip, and an active capacitance provided tothe tip for improved touch detection. An actuator 60 interfaces withprocessor 58 and writing tip 56 to change the size of the writing tipand other configuration settings. A pressure sensor 62 interfaces withwriting tip 56 and processor 58 to detect an amount of pressure actingagainst writing tip 56. A WNIC 64, such as a Bluetooth transceiver,interfaces with processor 58 to report the pressure sensor readings fromstylus 52 to information handling system 10's WNIC 24. Monitoringpressure at touches detected by the touch detection of flexibletouchscreen display 44 supports tracking of wear related to pressureplaced against the POLED material. Similar monitoring of finger pressesmay be performed by estimating finger pressure, such as by the size ofthe press, or measuring pressure with the touchscreen touch detectioncircuitry.

Based upon historical sensor data monitoring and a model of expectedPOLED material responses, operating constraints are determined forcurrently sensed conditions and applied to modify operations atinformation handling system 10 with respect to flexible touchscreendisplay 44. For example, when current operating conditions indicate thatfolding or unfolding flexible touchscreen display 44 could result indamage, a hinge brake 40 restricts movement of hinge assembly 36 toprotect against the damage. For example, hinge brake 40 may bind gearsof hinge assembly 36 to prevent rotation or increase friction of atorque plate to make rotation more difficult and/or slow. Similarly,magnet locks 42 on opposing housing portions 14 may magnetically-attractthe housing portions to each other to prevent movement of housingportions 14 towards an open position. These magnet locks 42 may also beused to force some separation between the housing portions 14 if housing12 is in a closed position for an excessive time so that the foldingradius of flexible touchscreen display 44 does not compress to too smallof a size.

In one example embodiment, hinge brake 40 prevents rotation about hingeassembly 36 due to a sensed thermal condition having too low of atemperature. At low thermal states, POLED material may break if foldingis attempted, such as if information handling system 10 is closed in anoff state for an extended time in a low ambient temperature condition.Embedded controller 32 interfaces with hinge brake 40 to have an “on”interrupt sent from hinge brake 40 when an attempt to open the housingportions 14 is prevented by hinge brake 40. Upon powering up anddetecting a locked hinge assembly 36, embedded controller 32 mayinitiate active warming of the POLED material so that hinge brake 40releases to allow opening of housing portions 14. Warming may beperformed by applying power to processing components, such as CPU 20 andGPU 30 near the folding region so that dissipation of power by theprocessing components releases thermal energy. As another alternative, aset of heating elements 48 may be activated for the direct purpose ofcreating heat at the POLED material. In some instances, embeddedcontroller 32 may read temperature sensors 46 to determine where inPOLED material the thermal state is too cold and selectively apply onlysome heating elements 48 to those areas. If the POLED material thermalstate is too hot, cooling elements 50 may instead be activated to reducethe thermal state within housing 12. For instance, small piezo coolingfans may generated cooling airflow at flexible touchscreen display 44while a system cooling fan 51 draws cooling airflow into housing 12. Inone example embodiment, embedded controller 32 may remain active wheninformation handling system 10 is in an off state so that the OLEDmaterial is automatically kept at a thermal state at which folding andunfolding is supported. Such constant monitoring for any extended timeperiod will typically require external power interfaced with informationhandling system 10.

Referring now to FIG. 2, a block diagram depicts hardware, firmware andsoftware layers of an information handling system 10 having flexibledisplay monitoring and management. The example embodiment hardware layerincludes processing components and other hardware components describedabove with respect to FIG. 1, such as CPU 20 that executes instructionsto process information, RAM 22 that stores the instructions andinformation, GPU 30 that processes visual information to define visualinformation for presentation on flexible touchscreen display 44 andembedded controller 32 that manages power and thermal conditions at theprocessing components. A touch controller 66 interfaces with flexibletouchscreen display 44 to scan for touch inputs, such as with capacitivetouch detection. WNIC 24 provides communication through wirelesssignals, such as through WiFi and Bluetooth. As describe above,temperature sensors 46 and rotational orientation sensor 38 detectoperating conditions at information handling system 10 while heatingelements 48, such as resistive heaters, cooling elements 50 and 51, suchas air moving devices, hinge brake 40 and housing magnet lock 42 adaptinformation handling system 10 operations to achieve desired operatingconstraints. In addition to the hardware elements within informationhandling system 10, stylus 52 includes its processor 58 that executesinstructions, typically embedded code, to provide additional monitoringand modifications related to flexible touchscreen display 44. Asdescribed above, writing tip 56 includes an assembly of contact pointshaving different levels of precision selected by processor 58 throughactuator 60. In addition to pressure sensor 62, stylus 52 includes adistance sensor 68 that detects a distance to a writing surface, such asan infrared time of flight sensor. WNIC 64 communicates pressure sensorand distance sensor output to information handling system 10 withwireless signals. A haptic motor 70 and LED indicator 72 providefeedback to an end user of stylus 52, such as if POLED film materialrestricts stylus interactions with flexible touchscreen display 44. Forinstance, if a pressure operating constraint exists at flexibletouchscreen display 44, such as due to an excess thermal state, wirelesscommunication to stylus 52 actuates a larger writing tip 56 and issues awarning to the end user with haptic feedback and an LED indication whenpressure becomes excessive.

The firmware layer of information handling system 10 receives operatingcondition sensed data from various sensors, such as temperature sensors46, rotational orientation sensor 38 and touch controller 66, andapplies the operating conditions to manage operation of flexibletouchscreen display 44. Specifically, the POLED material of the flexibledisplay film of flexible touchscreen display 44 is managed by localfirmware to adapt to sensed operating conditions; in addition, thefirmware layer communicates sensed conditions to a software layer thatprovides more computation-intense analysis and adaptive operations withinstructions back to the firmware layer. In various embodiments,instructions to perform the monitoring of operational conditions andmodifications to maintain operational constraints may be divided betweenfirmware, such as embedded code stored in flash memory and executed onembedded controller 32 or other processing components, and software,such as in the operating system with drivers for various processingcomponents. In the example embodiment, the firmware layer includes apressure manager 74 that receives pressure values from pressure sensor62 and, if available, from touch controller 66, and applies the pressurevalues with associated touch positions to detect conditions that violatedetermined pressure constraints. A thermal manager 76 executes tomonitor thermal conditions sensed by temperature sensors 46 and applyheat from heating elements 48 or cooling from cooling elements 50 and 51based on a comparison of sensed thermal conditions with thermalconstraints. For instance, POLED material film thermal management isprovided as an extension of system thermal management typically found inconventional information handling systems to keep other processingcomponents within thermal constraints. A power manager 78 monitors powerconsumption of processing components, which provides feedback ofexpected thermal conditions. For instance, power manager 78 monitorsflexible touchscreen display 44 brightness, on-pixel-ratios (OPR), andpower draw to estimate thermal conditions of POLED material based uponpower dissipation. A hinge manager 80 interfaces with rotationalorientation sensor 38 to detect the hinge position and with hinge brake40 and housing magnet lock 42 to adjust hinge motion if an operatingconstraint is violated by hinge motion. A stylus tip position manager 82monitors pressure constraints to adjust the stylus position if a touchedportion of flexible touchscreen display 44 has a pressure constraintthat may be violated by a stylus touch.

The software layer, through access to operating system functions andprocessing capabilities of CPU 20, provides higher level analysis ofoperating conditions, including on a historical basis, to determineoperating condition constraints. A display manager 84 executes on CPU 20to receive sensed operating conditions from the firmware layer and storethe sensed operating conditions for application by a flexible displaythermal model 86. Flexible display thermal model 86 applies historicalsensed operating conditions against known POLED material characteristicsto determine operating constraints 88, which define limits of sensedconditions associated with risk to damage of the POLED material. Displaymanager 84 provides the operating constraints 88 to the firmware layerwhere rapid comparisons of sensed conditions against the operatingconstraints can be performed to initiate adaptive operations asoperating constraint thresholds are met. In addition, the software layerincludes non-productive code 90, such as an unconstrained or infinitelogic loop, that executes on processing components to increase thermalenergy dissipation at the processing components. Non-productive code 90may include portions that operate on CPU 20, GPU 30, embedded controller32 and other processing components. A flexible display machine learningmodule 92 performs more in depth analysis based upon actual sensedoperating conditions, such as by accessing artificial intelligence andnetwork-based resources. A user interface 94 provides an end user withaccess to display manager 84 to adjust operating system constraints andoverride automated adaptive correction for achieving end user desiredoperating conditions. In the example embodiment, touch driver 96executes within the operating system to provide touch information assensed from touch controller 66 to display manager 84. As describedabove, the touch information may include finger touches made at flexibletouchscreen display 44.

To illustrate operating system monitoring and management by thehardware, software and firmware layers of FIG. 2, some examples areprovided that show tracked operating conditions and panelcharacteristics. Referring now to FIG. 3, a flexible touchscreen display44 is depicted divided up into fifteen regions 98 that each monitoredand tracked separately for detected operating conditions. A foldingregion 100 located over the hinge assembly is of particular interestsince this region experiences most of the stresses associated withfolding of the POLED material. Further, an airgap typically exists underfolding region 100 while the other regions 98 that do not fold have asolid support that helps to resist touch pressure and decreases theeffect of touches over time on the durability of the POLED material. Inmonitoring POLED material degradation and in determining operatingconstraints, such as maximum touch pressures, the amount of fold of thePOLED material in folding region 100 is a factor that is considered.Referring now to FIG. 4, an example thermal model table is depicted thatlists thermal conditions expected for display film operating conditionsbased upon the plural regions. In the example embodiment, for each ofplural regions an expected thermal condition, such as skin temperatureand time until saturation, is modeled based upon operating conditions ofthe flexible display, such as the OPR, housing configuration, CPU powerdissipation and charge state. Referring now to FIG. 5, a panelcharacterization table depicts examples of stored information gatheredfrom sensors that monitor the flexible display. In the exampleembodiment, for each of plural zones 98 of flexible touchscreen display,operating conditions are stored that reflect actual usage of theflexible display POLED material film. For example, the operatingconditions include pressure applied to the display film, brightness,temperatures, number of fold incidences, stylus (pen) interactions, timein a folded or planar state, etc. . . . . In one embodiment, currentcolor compensation is tracked for each separate region. OLED filmsperiodically perform a color compensation determination for each pixelby passing a signal through each pixel and measuring the response acrossthe pixel. Current color compensation tends to be a time consumingprocess that is performed across an entire display area. In the exampleembodiment, the impact on an end user may be reduced by performingcurrent color compensation in just one region so that the process isperformed gradually over a series of operations, such as one zone persystem power up. Further, since color compensation will impact thermalconditions output at a display film, more accurate thermal modeling maybe performed at a fold region by performing color compensation in thefold region more often than in other regions.

Considering FIGS. 1-5, some examples of POLED material thermaloptimization and degradation modification of operating constraints willhelp illustrate improvements provided by the present disclosure withrespect to foldable display film integration into an informationhandling system. The construction of a foldable display with POLEDmaterial presents difficulty with thermal management and material burnin due to difficult heat transfer properties of plastic and its limitedoverall heat dissipation. Thermal management is enhanced to supportdynamic throttling or increased use of a flexible display and othersubsystems to optimize POLED thermal state with balanced skintemperature across a display film by accurately characterizing POLEDthermal characteristics within an information handling system. Asdescribed above, firmware and software elements collect necessary datato adapt an initial calibration model so that various settings indifferent subsystems including the flexible display film adapt basedupon usage mode. As described above, in one example embodiment, theflexible display film is divided into plural regions to track POLEDmaterial surface temperatures with thermocouples so that thetemperatures are stored over time with related usage data, such as OPR,screen brightness levels, utilization rate of subsystems, physical coverof the display (such as an arm placed over top), in different ambienttemperatures and device orientations. Based upon this historical data,thermal characteristics of the flexible display film is modeled, such aswithin a DPTF system, and leveraged so that the thermal effects ofchanges to operating conditions can be predicted and applied to maintainthe flexible display film within thermal constraints.

Once a thermal model is developed for the flexible display film, thethermal model is applied to determine how operating conditions may bemodified to achieve POLED material thermal conditions within definedconstraints. For example, if skin temperatures become excessively highor low, or are expected to do so, then the operating conditions aresensed and, for each monitored display zone, modified to achieve thermalconstraints. For instance, display brightness may be adjusted in eachzone, subsystems under particular display zones may operate on anaccelerated or throttled basis to adjust their thermal profile. Asanother example, active heating and cooling elements may adjust flexibledisplay film thermal conditions at each zone by creating or removingthermal energy. In one example embodiment, a maximum difference intemperatures between display zones is set, such as based upon deviceposition, device orientation, processing component workload, userselected configurations, selection of display dark or light mode, andother operating conditions. If the threshold for difference intemperature is detected, operating conditions are changed to bring thedifference in temperatures between zones within the threshold. Forinstance, content may be moved based upon the thermal energy associatedwith presentation of the content, subsystems may adjust their powerdraw, brightness may be adjusted between the zones or other adaptationsmay be performed to bring the hottest and coldest zones to within thethermal constraint. In one embodiment, power draw by components and OPRin each zone may be used to predict and/or detect hotspots on thedisplay film. Operating condition data may be collected in fineincrements and increased detail from time to time so that OLED materialcharacteristics models may be updated by machine learning algorithms forimproved thermal condition control. In various embodiments, prioritiesfor adapting operating conditions may vary based upon content presentedat the display, such as a video playback, which calls for use of theentire display surface, versus a desktop, which offers flexibility aboutthe location of presentation of visual images.

Over time and system use, POLED material characteristics will change,such as due to exposure to raised or lowered temperatures and folding ofthe plastic substrate. The present disclosure tracks operationalconditions over time to predict and/or detect POLED material degradationso that operating constraints may be set at usage-adjusted values thatprolong POLED material useful life. Once POLED material degradation ischaracterized, it may then be further applied to optimize usage of astylus or finger touch interaction, placement of a user interface, panelcolor compensation detection and execution timeframe, and display filmdiagnostics. With respect to characterizing POLED material degradationrelated to thermal conditions, three examples of operating conditionsare illustrated as tracked in each of the plural zones. One example isthe total pixel on time as tracked by the graphics processor and itsoperating system driver. Another example is the average pixel brightnesslevel, again as tracked by the graphics processor and its driver. Athird example is the average operating temperature for each of theplural zones. Operating temperature is also tracked with respect todifferentials between the zones where temperature differentials may haveadditional degradation effects over the effect of temperature itself. Inaddition, thermal characteristics tracking has a further modificationeffect for the plural zones located within a folding region or a regionwhere there is no substantial support behind the flexible display film.

With respect to POLED material degradation related to folding of thedisplay film, a number of different operating conditions may be tracked.One example is tracking touches at the flexible display film by a stylusas well as by human touches. For instance, touches are tracked by zonefor total time with any pressure information associated with thetouches, such pressure sensed at the stylus and communicated wirelesslyto the information handling system or pressure detected directly by thedisplay. Again, touches at a folding region of the flexible display havea different modification effect than touches where the POLED materialhas a more substantial or fixed backing support, and the state of thefold at the time of the touch may have different impacts. Similarly,fold state impacts constraints set for a folding area, such as where afolded state of POLED material may have a greater degradation effectresponsive to a touch than a planar state. In one example embodiment,touches are tracked based upon a detected pressure, a detected touchtime, a type of touch (i.e., stylus, type of stylus tip, finger, bulkitem like a cup, etc. . . . ), and a pressure of the touch. In anotherexample embodiment, POLED material touches may be aggregated, such as bytotal number of touches with each touch assigned a number based upon itsduration and pressure. Similarly, touches may be aggregated to timevalue, such as by tracking touch time with a multiplier applied basedupon the pressure applied at the touch. Another example is trackingaverage stylus pressure applied to each zone. If a stylus includes adistance detector, such as an IR TOF detection device, waviness of theflexible display film is detected and tracked based upon distance dataprovided from the stylus. The number of folds of the flexible displayfilm, the amount of each fold, the total duration of the folds and thetime since the last change in a fold state are each derived fromrotational orientations sensed by the rotational orientation sensor.

In various embodiments, POLED material degradation will impact variousoperating constraints. For instance, a maximum stylus pressure decreasesover time based upon application of the operating conditions trackedabove. An initial maximum pressure is set at manufacture, such as basedupon testing of a new POLED material. As the POLED material degradesover time, the maximum pressure decreases so that an end user may bewarned if touch inputs risk damage to the POLED material, such as mayhappen in a fold region having degradation due to folding andexperiencing current operating conditions of high temperature. Asanother example, POLED material degradation may result in initiation ofcolor compensation for one of the plural regions based upon itsoperating conditions independent of the flexible display film as awhole. This limited color compensation to within just one of pluralflexible display regions takes a relatively small time compared with acomplete color compensation across the whole flexible display film. Froma system perspective, POLED material degradation offers opportunities tomanage system operations so that POLED material life is extended. Forinstance, user interfaces may be shifted to selected portions of theflexible display film so that bright images or images associated withgreater degradation are presented at display zones having lessdegradation. Similarly, zones having greater available maximum pressuresmay have user interfaces presented for stylus touches while zones havinglower maximum pressures may have user interfaces presented that are notassociated with touches.

Once POLED material is characterized and its degradation modeled todefine modified operating constraints, the modified operatingconstraints are applied to protect the POLED material of the flexibledisplay film from non-ideal operating conditions. Some examples ofnon-ideal operating conditions include high or low temperatures or anextended time period, such as 24 hours, in a folded state. For instance,as is illustrated by FIGS. 9A and 9B, extended time periods in thefolded orientation may result in compression of the fold radius withrelated stress on the POLED material, especially if the rotation toremove the fold is attempted at high or low temperatures. One example ofa protective action based upon sensed operating conditions is a magneticlatch that pushes housing portions apart if a folded state is maintainedfor a predetermined time period, such as time determined fromtemperature and POLED material degradation information. By pushing thehousings apart, such as with aligned like polarity, the radius of thePOLED material is increased, which decreases the impact of the foldedstate on the POLED material. Another example of a protective action is ahinge brake that prevents changes to the folded state of the POLEDmaterial if currently sensed conditions exceed predetermined thresholds,such as a high or low temperature threshold determined in part fromPOLED degradation. For instance, a hinge brake engages the hinge, suchas by binding hinge gears or increase friction torque that resists hingerotation, until heating and/or cooling elements bring POLED material toa thermal state that will allow folding/unfolding. In one exampleembodiment, an end user may select from a user interface active thermalmanagement of POLED material while the information handling system is inthe folded state so that the end user will not experience delays by thehinge brake from changing the fold position, such as when theinformation handling system is in an off state. Notification to the enduser of a delay caused by the hinge brake may be provided with an LED orspeaker disposed in the housing, such as by sounding an alarm if anattempt to change the fold state will violate POLED material operatingconstraints. As described above, thermal conditions at a particularflexible display film zone may be adjusted with active heating orcooling or by adjusting operating conditions of a processing componentnear the zone.

Referring now to FIG. 6, a flow diagram depicts a process for monitoringand adapting a flexible display film operation based upon thermaloperating conditions and constraints. The process starts at step 102 andcontinues to step 104 to collect real time operating conditions for theflexible display film, such as thermal sensor output, touch detectionoutput, and virtual sensor output derived from power consumption. Atstep 106, a determination is made of whether the average skintemperature of any zone of the flexible display is higher than themaximum or minimum temperature constraint set for that zone. If atemperature constraint is violated, then the process continues to step108 to take corrective actions. Note that corrective actions aredetermined in part upon end user configuration settings, which areindicated at 110 and a thermal model table indicated at 112. User inputsto change configurations made at 110 are applied to generate the thermalmodel table at 112 to define the thermal-related limits for acceptableoperating conditions. These user settings and the resulting thermalmodel table may adjust as needed to ensure operations within safeconstraints that protect the system from damage, such as withadjustments as POLED material deteriorates over time at different ratesbased upon detected operating conditions. In the example embodiment, thecorrective action involves adjusting brightness and subsystem operationsto adjust thermal conditions near the display portion so that thedisplay portion temperature returns to within the operating constraintrange. For instance, if thermal conditions are too high, brightness isdecreased in the region and nearby processing components are throttled;if thermal conditions are too low, brightness is increased in theregions and nearby processing components execute non-productive code toincrease their thermal output. At step 114, a determination is made ofwhether the average temperature difference is greater than a maximumtemperature difference constraint between the zones that have thehighest and lowest temperatures. In one alternative embodiment, asimilar comparison may be made for all display zones relative to theiradjacent display zones so that a temperature difference in a particulararea of the flexible display does not exceed a threshold. If thetemperature difference falls within constraints, the process returns tostep 104 to continue monitoring the flexible display film thermal state.If at step 114 the temperature difference exceeds the operatingconstraint threshold, the process continues to step 116, based upon theuser configuration at step 110 and the thermal model at step 112, totake corrective action to bring the temperature difference to withinoperating constraints, such as by altering brightness and processingcomponent operations. From step 116, the process continues to step 118to update the thermal model table at step 112, and returns to step 102to initiate monitoring of operating conditions based upon the updatedthermal model.

Referring now to FIG. 7, a flow diagram depicts a process for adaptinginformation handling system operating conditions in response todetection of non-ideal thermal conditions. The process starts at step120 and continues to step 122 to determine if the POLED material fallswithin thermal constraints that suggest folding/unfolding of theflexible display film may be performed without damage to the POLEDmaterial. In one embodiment, the process starts in response togeneration of an interrupt at a GPIO by a detection of a rotationattempt at the hinge, such as to initiate a determination of theflexible display film thermal state before rotation of the hinge isallowed. If thermal conditions of the POLED material falls withinthermal constraints that allow folding/unfolding, the process continuesto step 132 to release the hinge and allow rotation of the hinge. In oneembodiment, the release of the hinge may be with a torque to resistrotation that varies based upon the flexible display film thermal state,such as to reduce folding/unfolding motion speed if thermal conditionsare near a constraint.

If at step 122 thermal conditions violate a thermal constraint relatedto hinge rotation, the process continues to step 124 to ensure that thehinge brake locks the hinge to restrict hinge rotation. The process thencontinues to step 126 to determine if the end user has configured activeheating and/or cooling to adjust the flexible display thermal state. Ifactive heating and/or cooling is not enabled, the process returns tostep 122 to continue monitoring the flexible display film thermal state.If active heating and/or cooling are activated, the process continues tostep 128 to use the active heating and/or cooling to get the POLEDmaterial to a thermal state that is conducive to folding/unfoldingwithout damage. At step 130 a determination is made of whether the POLEDmaterial thermal state falls within thermal constraints forfolding/unfolding. If the thermal constraints are not met, the processreturns to step 128 to continue monitoring the thermal state response tothe thermal heating/cooling. Once the flexible display film POLEDmaterial falls within the thermal constraints to allowfolding/unfolding, the process continues to step 132 to release thehinge and then to step 120 to continue monitoring the POLED materialthermal state relative to folding/unfolding thermal constraints.

Referring now to FIG. 8, a flow diagram depicts a process for adaptinginformation handling system operating conditions based upon time in afolded position. The process begins at step 134 and continues to step136 to determine whether the flexible display film POLED material hasbeen in a predetermined fold state for a predetermined time constraint.The time may be based upon thermal conditions, POLED materialdegradation, and the amount of fold involved. If the folded positiontime constraint has been exceeded, the process continues to step 138 toactivate a mechanism that applies some separation between the housingportions in the folded position. For instance, like magnetic polaritiesare aligned that create a separation force between the housing portions,thus slightly unfolding the flexible display film. At step 140, adetermination is made of whether activation to separate the housingportions resulted in some unfolding of the flexible display film. Ifsome unfolding is accomplished, then at step 142 a notification ispushed to the end user of the information handling system regarding thefold state of the flexible display. If unfolding is not accomplished,then at step 144 an alert notification is provided to the end userregarding the fold state of the flexible display film and suggesting enduser intervention to release some of the fold by separating the housingportions from the fully closed position. The process ends at step 146.

Referring now to FIGS. 9A and 9B, an example side view of an informationhandling system depicts flexible display film fold radius changesrelated to time in a folded position. FIG. 9A depicts a comparison of anactual fold radius 148 of a flexible touchscreen display 44 having aflexible display film of POLED material and an ideal radius 150. Theideal radius is determined from the POLED material's foldingcharacteristics to provide folding without excess distortion forces thatcan degrade the POLED material. In FIG. 9A, upon initial folding offlexible touchscreen display 44 a radius of 2.406 is achieved versus anideal radius of 3.011 for a ratio of 79.9%. After 24 hours in the foldedconfiguration, the real radius adjusts to 2.562 versus an ideal radiusof 3.030 for a ratio of 84.6%. Forcing the housing portions apartslightly after an extended time period in a folded configuration helpsto avoid compression of the POLED material that can result in damage tothe flexible display film.

Referring now to FIGS. 10A, 10B, 10C and 10D, side cutaway views depicta stylus 52 having automated interactions with a flexible display film.In the example embodiment depicted by FIGS. 10A and 10B, a tip extendsfrom tip assembly 56 out of stylus housing 54 through an end of thestylus housing 54. Tip assembly 56 position is controlled with anactuator 152 of shape memory alloy (SMA), sometimes referred to asmuscle wire, such as nickel titanium or Nitonol, which changescrystalline form when heated. A return spring 154 biases writing tipassembly 56 to extend outward. Stylus processor 58 applies current froma battery 156 to actuator 152 so that heat generated by the currentchanges the crystalline form of the SMA wire causing it to rotate (asshown by arrow 158) and retract tip assembly 56 as depicted by FIG. 10B.With tip assembly 56 retracted, stylus 52 may still be used to makeinputs at a display touchscreen surface where the rounded stylus housing54 end has a larger surface area that distributes pressure from a touchacross a greater surface area of the display than does the extended tip.Thus, for instance, stylus processor 58 may retract the extended tip ifa pressure constraint is approached at the flexible display film so thatthe rounded housing end allows stylus use with greater distribution oftouch pressures. In the example embodiment depicted by FIGS. 10C and 10Ddepict an alternative embodiment in which a latch 160 engages with thewriting tip assembly to hold the writing tip in an extended position ora retracted position. In FIG. 10C, return spring 154 biases latch 160 tohold the tip extended. Stylus processor 58 activates an electromagnet oflatch 160 to retract the latch and allow the tip to retract. In oneembodiment, latch 160 is activated to retract the writing tip from theextended position if a pressure sensor monitor pressure working againstthe tip detects a pressure in excess of a flexible display touchconstraint.

Referring now to FIGS. 11A and 11B, side cutaway views depict the stylus52 having an extended tip 164 configured to selectively extend past aprecision tip 162. In the example embodiment, an electro-permanentmagnet coil 166 adapts its polarity to retract an extended tip area 164as shown in FIG. 11A and extend the extended tip area 164 as shown inFIG. 11B. Expanded tip area 164 has a wider touch footprint that spreadstouch pressures across a flexible display film than precision tip 162.In one embodiment, a pressure sensor interfaced with stylus processor 58senses pressure in excess of a pressure constraint and, in response,stylus processor 58 changes the polarity of electro-permanent magnet 166to extend expanded tip area 164 and maintain pressure at the flexibletouchscreen display within a defined constraint.

Referring now to FIG. 12, a side perspective view depicts monitoring offlexible display film surface planarity by measuring a distance with adistance sensor 68. As stylus 52 touches the touchscreen displaysurface, any deformations, such as a surface wave 168 caused bydistortions in the plastic substrate, are detected by variations in thedistance of the stylus to the touchscreen display as the stylus movesalong the plane of the touchscreen display. Stylus 52 communicates thechanges in distance to the information handling system, which relatesthe distances to touch positions at the touchscreen display. Detecteddeformations may be tracked as POLED degradations and compensated for,such as by narrow the temperature constraints in which the flexibledisplay film is allowed to fold. Referring now to FIG. 13, an example ofa relationship between pressures detected at a stylus tip and loadplaced on the flexible display is depicted. Such a relationship may beapplied by a display manager of an information handling system so that astylus interacting with the information handling system has pressureconstraints that correlate to pressures sensed by the integratedpressure sensor. In addition to retracting a sharp tip at a pressureconstraint to reduce load through an expanded tip, stylus 52 may providea haptic or LED warning when a pressure constraint is met. In onealternative embodiment, stylus 52 sends pressure readings to theinformation handling system, which commands a tip retraction if apressure constraint is met. Alternatively, the information handlingsystem updates the pressure constraint applied by stylus 52 based uponthe zone in which the stylus is detected and the type of touch detected,such as a small area of an active stylus tip or a larger area of anexpanded tip.

Referring now to FIG. 14, a flow diagram depicts a process for managinga stylus tip engagement at a flexible display film. The process startsat step 170, such as with detection of stylus pen use. At step 172 theinformation handling system gets the stylus location, pressure andwaviness information from the stylus, such as through wirelesscommunication by Bluetooth, or, if available, a stylus communicationprotocol that leverages the stylus active capacitance tip. At step 174,the stylus writing tip is adjusted to operate within the maximumpressure constraint of the flexible display film at the stylus touchlocation. For example, tip retraction and haptic warning at the stylusmay be initiated with logic executing on the stylus based upon a maximumpressure communicated to the stylus and actual pressure detected at thestylus. Alternatively, pressure readings are provided from the stylus tothe information handling system for comparison with pressure constraintsand a command by the information handling system to adjust the styluswriting tip based upon the pressure constraints. At step 176,temperature sensor measurements along with other flexible display filmoperating conditions, such as OPR and brightness are taken and stored.At step 178 a hinge orientation measurement is taken and stored. At step180, the flexible display film operating conditions, including thermalstate information and hinge rotational orientation, are applied at thepanel characterization table to determine updated operating constraints,including pressure constraints. The process then returns to step 170 tocontinue monitoring stylus operation. At 182, the panel characterizationtable is stored as adjusted with the sensed operating conditions andupdated pressure constraints so that monitoring of the pressureconstraint at step 170 uses an updated value. For instance, anon-transitory memory, such as a flash memory accessible by an embeddedcontroller or processor ISH, stores panel characterization values andconstraints for access by the system as needed.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

What is claimed is:
 1. An information handling system comprising: firstand second housing portions; a hinge rotationally coupling the first andsecond housing portions to rotate between closed and open positions; adisplay disposed over the first and second housing portions and thehinge, the display having a flat configuration in the open position anda folded configuration in the closed position; one or more thermalsensors operable to detect a thermal state at the display; a hinge brakeinterfaced with the hinge and operable to selectively lock the hinge torestrict rotation of the first and second housing portions; and a hingemanager interfaced with the one or more thermal sensors and the hingebrake, the hinge manager operable to apply the hinge brake to restrictrotation of the first and second housing portions if the one or morethermal sensors detect a predetermined thermal state.
 2. The informationhandling system of claim 1 further comprising: a hinge position timeroperable to track an amount of time that the hinge has a rotationalorientation; wherein the predetermined thermal state varies based uponthe amount of time.
 3. The information handling system of claim 1further comprising: a heating element disposed proximate the display andoperable to direct thermal energy towards the display; wherein the hingemanager applies the heating element to heat the display when the hingebrake restricts rotation due to a low thermal state.
 4. The informationhandling system of claim 3 further comprising: a cooling elementdisposed proximate the display and operable to draw thermal energy fromthe display; wherein the hinge manager applies the cooling element tocool the display when the hinge brake restricts rotation due to a highthermal state.
 5. The information handling system of claim 4 wherein thehinge manager operates on an embedded processor to maintain the displaytemperature in a range during both power down states and power up statesof the information handling system.
 6. The information handling systemof claim 4 wherein the hinge manager includes an active managerinterfaced with the heating element and the cooling element, the activemanager selectively engage to prevent a predetermined thermal state thatengages the hinge brake to prevent rotation of the first and secondhousing portions.
 7. The information handling system of claim 1 furthercomprising: a first magnet disposed in the first housing portion; and asecond magnet disposed in the second housing portion; wherein the hingemanager selectively aligns opposing polarities of the first and secondmagnets when the first and second housing portions have the closedposition for a predetermined time.
 8. The information handling system ofclaim 1 wherein: the hinge brake provides a variable torque at thehinge; and the hinge manager commands a variable torque based upon thepredetermined thermal state.
 9. The information handling system of claim1 wherein: the display comprises a plastic organic light emitting diodedisplay film; the hinge manager comprises an embedded controllerinterfaced with a central processing unit; and the hinge managercommands the central processing unit to execute heat generating code todirect thermal energy at the display.
 10. A method for managinginformation handling system rotational orientation, the methodcomprising: monitoring thermal conditions associated with a displayintegrated in the information handling system to detect a thermal state;and in response to a first predetermined thermal state detected by themonitoring, restricting changes to the rotational orientation.
 11. Themethod of claim 10 further comprising: in response to the restrictingchanges to the rotational orientation, generating heat proximate thedisplay; in response to the generating heat, monitoring for a secondpredetermined thermal state; and in response to the second predeterminedthermal state, ceasing the restricting changes to the rotationalorientation.
 12. The method of claim 11 wherein the generating heatproximate the display further comprises executing a heat generating codeon a central processing unit of the information handling system.
 13. Themethod of claim 11 wherein the generating heat proximate the displayfurther comprises applying current to a heat generation element.
 14. Themethod of claim 11 further comprising: in response to the restrictingchanges to the rotational orientation, generating a cooling airflowproximate the display to draw thermal energy from the display; inresponse to the generating a cooling airflow, monitoring for a secondpredetermined thermal state; and in response to the second predeterminedthermal state, ceasing the restricting changes to the rotationalorientation.
 15. The method of claim 10 further comprising: monitoringrotational orientation to detect a time during which the rotationalorientation is maintained; and adjusting thermal conditions associatedwith the display that determine the first predetermined thermal statebased upon the time.
 16. The method of claim 10 wherein restrictingchanges to the rotational orientation further comprises locking a hingeof the information handling system at the rotational orientation. 17.The method of claim 10 wherein restricting changes to the rotationalorientation further comprises increasing torque applied at a hinge ofthe information handling system, the torque working against rotationalmovement.
 18. A display fold management system comprising: a hingehaving a brake, the brake selectively engaged to restrict hingerotation, the hinge having a support side that supports a flexibledisplay in a planar position and a folded position; one or more thermalsensors disposed to measure a thermal state of the flexible display; anda controller executing a hinge manager stored in non-transitory memory,the controller interfaced with the brake and the one or more thermalsensors, the hinge manager locking the hinge brake in response to theone or more thermal sensors detecting a first predetermined thermalstate.
 19. The display fold management system of claim 18 furthercomprising: a heating element operable to generate thermal energyproximate the flexible display and interfaced with the controller;wherein the hinge manager in response to the first predetermined thermalstate commands the heating element to generate thermal energy to achievea second predetermined thermal state, the hinge manager releasing thehinge brake in response to the second predetermined state.
 20. Thedisplay fold management system of claim 18 further comprising: a coolingelement operable to remove thermal energy proximate the flexible displayand interfaced with the controller; wherein the hinge manager inresponse to the first predetermined thermal state commands the coolingelement to remove thermal energy to achieve a second predeterminedthermal state, the hinge manager releasing the hinge brake in responseto the second predetermined state.